Superior Pebax‐1657/amine‐modified halloysite nanotubes mixed‐matrix membranes to improve the CO₂/CH₄ separation efficiency

Abstract

In the present study, halloysite nanotubes (HNTs) were firstly functionalized using N‐β‐(aminoethyl)‐γ‐aminopropyltrimethoxy silane and then employed as nanofillers to fabricate mixed‐matrix membranes including poly (ether‐block‐amide) polymer as the primary material. To characterize the HNTs, as well as the obtained membranes, thermal gravimetric analysis, Fourier‐transform infrared spectroscopy, X‐ray powder diffraction, and Field emission scanning electron microscopy analyses were employed. Effects of the modified and pure HNTs loadings, as well as feed pressure on CH4 and CO2 permeabilities and ideal CO2/CH4 selectivity of the prepared membranes, were surveyed. The experimental permeation results indicated that incorporation of 1.5 wt% of amine‐functionalized HNTs into the polymer matrix improves CO2 permeability and the ideal selectivity by nearly 37 and 24%, respectively, due to the higher CO2 adsorption capacity of the amine‐functionalized HNTs.

Fabrication and characterization of dual layer PEBAX‐SiO2/polyethersulfone nanocomposite membranes for separation of CO2/CH4 gases

“…47,63 In addition, CO 2 is a polar gas and can have good interaction with the polar segments of PEBAX such as ethylene oxide and carbonyl groups so its solubility is increased. 17,56,64,65…”

A Review of the Recent Progress in the Development of Nanocomposites Based on Poly(ether-block-amide) Copolymers as Membranes for CO2 Separation

“…Halloysite nanotubes (HNT) were added at different loadings to a Pebax layer coated on polyetherimide (PEI) supports to produce thin-film composite membranes [ 89 ]. In another study, HNTs functionalized with N-β-(aminoethyl)-γ-aminopropyltrimethoxy silane were used [ 90 ].…”

“…The reduction in the crystallinity degree upon the addition of anion-pillared hybrid ultramicroporous materials to Pebax/PEGDEM was caused by broken interchain hydrogen bonds within the polymer matrix [ 92 ]. A reduced crystallinity in the MMMs has been ascribed to the breaking of inter-chain hydrogen bonding between the amide chains in PA blocks [ 57 , 90 ].…”

“…This finding is consistent with the overall CO 2 separation performance decline as GEFSIX-2-Cu-i loading increased from 1 to 10 wt%, due to the severe aggregation of the nanoparticles [ 92 ]. An increased inter-segmental gap of the polymer chains was evidenced for MMMs comprising NH 2 -HNTs, resulting in a larger amount of FFV [ 90 ]. This behavior is associated with reduced thermal stability.…”

“…The filler functionalization is an approach that is capable of improving dispersion. Indeed, the surface modification of the fillers improves the compatibility at the interface with the polymeric phase and increases the interlayer spacing, shifting toward higher filler contents with the occurrence of agglomeration [ 50 , 90 ]. GO agglomerated at a loading of 0.2 wt% in a Pebax 1657 matrix, whereas a uniform dispersion was still exhibited by the modified nanomaterial GO-IL at the same concentration [ 50 ].…”